C# Discussion Boards - CodeProject

Re: Centralising event handling in a Windows Form application

Jun Du12-Sep-06 15:53

12-Sep-06 15:53

For event/notification handling, there are .NET event model and Observer/Subject design pattern. How is yours different than these two?

Best,
Jun

Re: Centralising event handling in a Windows Form application

GazzaJ18-Sep-06 4:45

GazzaJ

18-Sep-06 4:45

I am effectively using the .NET event model. My question seems to be how to handle controls that are programatically created. Say the main hub of my application deals with the events that controls can generate and passes these to the other controls to process.

If the main hub programatically creates a user control, how does it know what events this can fire and hook up an event handler to these?

Re: Centralising event handling in a Windows Form application

Jun Du18-Sep-06 6:13

Jun Du

18-Sep-06 6:13

GazzaJ wrote:
controls can generate and passes these to the other controls to process

Hope this link can help.

GazzaJ wrote:
If the main hub programatically creates a user control, how does it know what events this can fire and hook up an event handler to these?

I believe that you need to raise and consume events in your custom control. This link might be able to help.

Best,
Jun

Re: Centralising event handling in a Windows Form application

lmoelleb12-Sep-06 21:21

lmoelleb

12-Sep-06 21:21

Take a look at the smart client software factory (Google it, the first search page should contain various resources regarding this).

No need to reinvent the wheel.

Re: Centralising event handling in a Windows Form application

GazzaJ18-Sep-06 4:46

GazzaJ

18-Sep-06 4:46

This looks good although I am still on .NET 1.1 at the moment.

How to get Image from other Image quickly

Libor Tinka12-Sep-06 6:23

Libor Tinka

12-Sep-06 6:23

I need to divide a very large image (say 5-7 mpx) into smaller pieces (24 bpp Image objects). Algorithm is not a problem, the speed of used GDI+ method is.

Using Graphics.DrawImage() is slow, even when no interpolation is done. The problem is not in the count of pieces, but in the size of huge source image. Doesn't matter how large the pieces are, because the long time is taken by the reading of pixels from source.

I've thought about using unsafe pixel access, but still hope there's some method for obtaining smaller image from larger one quickly.

Re: How to get Image from other Image quickly

Jun Du12-Sep-06 7:12

Jun Du

12-Sep-06 7:12

Libor Tinka wrote:
because the long time is taken by the reading of pixels from source

I wouldn't read pixels. Locate each small piece on the original image and draw it to a separate graphic buffer. Then, you may either save it to a file or render it to the screen.

Best,
Jun

Re: How to get Image from other Image quickly

Libor Tinka12-Sep-06 8:58

Libor Tinka

12-Sep-06 8:58

The drawing to separate buffer (doesn't matter how small the buffer is) is slow when working with large images. Drawing small area of 10 by 10 pixels from position [x,y] using

graphics.DrawImage(srcImage, new Rectangle(0, 0, 10, 10), x, y, 10, 10)

looks fast - try it on 7 megapixel image, it won't be.

Re: How to get Image from other Image quickly

Ranjan Banerji12-Sep-06 17:08

Ranjan Banerji

12-Sep-06 17:08

If you want speed then dont use GDI. Use unsafe code. here is an example of using unsae code to handle bitmaps. Does not do what you want, but I am sure you can figure it out Smile | :)

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Compiler Error Numbers

Brady Kelly12-Sep-06 5:39

Brady Kelly

12-Sep-06 5:39

Is there any way to get error numbers for errors in the VS error list? I've thought of doing an add-in that sort of replaces the error list and looks up error numbers, but that seems a bit clumsy.

Re: Compiler Error Numbers

User 665812-Sep-06 5:47

User 6658

12-Sep-06 5:47

I don't know how to get them programmically (you might want to try to attach a StreamReader to the csc output).
But you can go to "View" -> "Output".
You will there get the raw output of csc

regards

modified 12-Sep-18 21:01pm.

Re: Compiler Error Numbers

Rick Crone14-Sep-06 8:16

Rick Crone

14-Sep-06 8:16

Right click the error message and Show Error Help.

At the top of the help window you will see a message like:

Visual C# Reference: Errors and Warnings
Compiler Error CS1501

Database Access in UITypeEditors

nlgarvey12-Sep-06 5:20

nlgarvey

12-Sep-06 5:20

I am creating Custom Workflow Activities for our company. One of the main hurdles to this is in order to make the activities easy to use, I need to access to a database. This way, I can present the users with choices for correctly configuring the activities. I have not done a lot with creating UITypeEditors. VS will be initially be used for configuring the properties.

Does anybody have any recommendations/tips for how to go about doing this?

Compiler Warnings

gantww12-Sep-06 5:06

gantww

12-Sep-06 5:06

Hello all,
I'm working on a project written by someone else that links to an encryption library using interop. I'm getting about 50 warnings about types in that assembly that cannot be marshalled by the runtime marshaller and will be passed as a pointer, blah blah.

The fact is, the program is still running. I would like to ignore these specific warnings during the build so I can find any others that may pop up. Replacing the encryption component or changing its interaction with the program is not allowed at this time, so any help would be very useful.

Thanks,
Will

Re: Compiler Warnings

User 665812-Sep-06 6:00

User 6658

12-Sep-06 6:00

In the project properties under "Build" you can enter the numbers of warnings to suppress.
There's an edit box named "Suppress warnings:"

#pragma warning disable 1234 will also work

regards

modified 12-Sep-18 21:01pm.

How to get a return value from a winservice at cmd batch: net start ...

MDT Daniel12-Sep-06 5:05

MDT Daniel

12-Sep-06 5:05

I have a windows service called "XcontrolService" programmed in C#.
From a cmd - Batch, i'll start the installed service with net start XcontrolService.
In the OnStart-Method of service, i will do some jobs and on the end i
would like to return a own defined value to batch.
OnStart returns void!, and ServiceBase.ExitCode does not match %ERRORLEVEL% from batch.

Can you help me about this problem?

Thanks!

Kind Regards
Daniel

How to create my own setup dialog form for Setup

Nicklez12-Sep-06 4:32

Nicklez

12-Sep-06 4:32

OK. I have an project and setup project for it. How can I add or create my own setup dialog in Setup User Interface pane? I want place on it controls like listbox, textbox, in different coordinates...

Walking down inhertiance path

smurfy3412-Sep-06 4:28

smurfy34

12-Sep-06 4:28

Hi:

I am trying to invoke a base class method, but I find I can only walk down 1 level of inheritance. Is there a way to go down more levels with some more explicit way of specifying which level I am interested?

eg.

public class a
{
protected virtual void Method1()
{
...
}

}

public class b: a
{
protected override void Method1()
{
...
}

}

public class c: b
{
protected override void Method1()
{
...
}
}

public class d: c
{
protected override void Method1()
{
...
}

protected void SomeMethod()
{
....
-- here I want to invoke Method1() of class b
base.Method1(); // this would invoke c.Method1()
}

}

Regards, smurfy

Re: Walking down inhertiance path

Colin Angus Mackay12-Sep-06 4:41

Colin Angus Mackay

12-Sep-06 4:41

smurfy34 wrote:
-- here I want to invoke Method1() of class b
base.Method1(); // this would invoke c.Method1()

That is correct. You call the imediate base, which calls the next base and so on. Skipping a class is not recommended and probably suggests that your design isn't quite right.

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How can I disable JavaScript error messages?

Dima Filipiuk12-Sep-06 4:24

Dima Filipiuk

12-Sep-06 4:24

How can I disable JavaScript error messages in axWebBrowser?

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Calling unmanaged dll functions in C#

Kasic Slobodan12-Sep-06 4:05

Kasic Slobodan

12-Sep-06 4:05

I have a dll that is written in c++ and I want to send a char *. Pointer of array of chars.
So, I need a equivalent of:

char *path = new char[300];
some_function(path);

for C# application.

Re: Calling unmanaged dll functions in C#

Nader Elshehabi12-Sep-06 8:35

Nader Elshehabi

12-Sep-06 8:35

Hello

Send it as StringBuilder.

Regards

Re: Calling unmanaged dll functions in C#

Kasic Slobodan13-Sep-06 4:03

Kasic Slobodan

13-Sep-06 4:03

Can you provide some code sample for this?
I've tried, but no luck.

Re: Calling unmanaged dll functions in C#

Nader Elshehabi13-Sep-06 5:43

Nader Elshehabi

13-Sep-06 5:43

Hello

StringBuilder path = new StringBuilder();
some_function(path);

Regards

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